The Chain of Rocks Bridge spans the Mississippi River on the north edge of St. Louis, Missouri. The eastern end of the bridge is on Chouteau Island, (part of Madison, Illinois), while the western end is on the Missouri shoreline.
The bridge was for a time the route used by U.S. Route 66 to cross over the Mississippi. Its most notable feature is a 22-degree bend occurring at the middle of the crossing. Originally a motor route, the bridge now carries walking and biking trails over the river. The bridge was added to the National Register of Historic Places in 2006.[Wikipedia}